Major vendors have made commercially available stereo speakers and stereo playback capabilities in mobile phones. The layout of mobile phone stereo speaker(s) are often asymmetric due to cost saving and design aesthetics. An example of an asymmetric layout comprises of (i) a small speaker at the top of the phone (e.g., an ear speaker) mounted parallel to a screen, and (ii) a second (main) speaker at the bottom of the phone facing downwards. However, such speaker layout(s) are acoustically challenging, including because:                the frequency magnitude response of both speakers can be substantially different, thereby negatively influencing the perceived spatial imaging of stereo or multi-channel content;        there are difficulties in order to correctly execute cross-talk cancellation algorithms for stereo widening and virtualization of multi-channel content or object-based content (e.g., Dolby Atmos) because these types of content are typically based on the assumption of a symmetric speaker layout;        the orientation and position dependency (e.g., when the phone is handheld v. put on a hard surface like a table) of the frequency responses may change the listening experience dramatically;        the frequency-dependent phase response of both speakers can vary considerably, negatively impacting the perceived stereo and virtualization imaging;        when the phone is held vertically (e.g. in portrait mode), there may be sub-optimal playback in terms of achieving maximum loudness if the speaker capabilities are vastly different and/or frequency dependent.        
Speaker correction typically involves applying static or dynamic correction filter(s) that are common to both speaker drivers. Such correction filter(s) are directed to modifying a perceived timbre by amplifying frequencies that are reproduced at relatively low levels of sound pressure. The filters are typically derived from measured frequency responses of the loudspeakers, followed by an optimization or tuning algorithm that computes a correction filter with the aforementioned goal of improving the perceived timbre. However, there are several limitations to such solutions:                unless the correction filters are allowed to be different for the two drivers, spatial imaging for asymmetric speaker layouts will not improve by applying a (common) correction filter;        the frequency response of two drivers with one common correction filter cannot be optimally used, (e.g., if one driver efficiently reproduces high frequencies, while the second driver is more capable in reproducing low frequencies, trying to play all frequencies equally by both drivers can give suboptimal results);        correction filters are typically zero, linear or minimum-phase filter designed to reduce complexity and memory requirements and hence phase difference compensation is not included, which can degrade the perceived spatial image of audio played over the two speakers;        correction filters are independent of use case(s) and are not personalized nor device-orientation/position dependent (e.g., if the phone is placed on a hard, flat surface such as a table, the effective frequency response of at least one of the drivers may change significantly); hence any static correction filters will typically be suboptimal in at least one use case for which the correction filters were not designed;        speaker virtualization by means of cross-talk cancellation may be enabled even when a device is held in portrait mode, compromising loudness and timbre but without any spatial benefit;        one or more speakers may be (partially) covered by the user (for example by the hand holding the phone) introducing a change in the frequency response of that particular speaker. Conversely, a user may use a hand to improve the response of a loudspeaker. No prior solution has means to detect such changes or accordingly adjust a device processing algorithm.        
Thus, there is a need for improved processing of audio data for replay on mobile devices. There is particular need for such improved processing of audio data for replay on mobile devices with asymmetric speaker configurations.